Battery operated NFC devices require lowest current consumption during operation and standby. Especially for NFC contactless access systems, changing batteries is a main running cost contributor of the NFC system. If this battery exchange rate can be reduced by lowering the overall current consumption of the system, the overall running costs of the NFC system will be reduced.
Currently, NFC devices require a low power standby configuration in order to detect external radio frequency (RF) fields. The host controller and the NFC frontend are in a low power mode requiring a battery supply present all the time causing a battery supply current consumption. Additional energy may be needed for supply voltage conditioning (e.g., low drop regulators, DC-to-DC (direct current to direct current) converters). Therefore, there is a continuous energy consumption that limits the total NFC device availability and lifetime.
Therefore, it is desirable to have devices and methods that can provide for an NFC device to be completely turned off (i.e., “zero” power configuration) when the NFC device is not detecting an external radio frequency (RF) field.